全麦中烷基间苯二酚液相荧光测定方法的建立

ESTABLISHMENT OF THE LIQUID FLUOROMETRIC METHOD FOR DETERMINATION OF ALKYLRESORCINOLS IN WHOLE WHEAT

目的为有效判断全麦产品的质量,建立其标记物-烷基间苯二酚(ARs)的分析方法。方法以小麦和黑小麦为主要研究对象,采用析因设计探讨了提取试剂(丙酮、乙醇、乙酸乙酯)、提取方法(超声30 min, 60 min,室温振荡过夜)、样品状态(颗粒、粉末)对ARs测定的影响,通过对比色谱条件和适宜荧光波长建立ARs检测条件,在完成方法学评价基础上对部分市售麦类作物ARs水平进行了测定。结果和乙醇、乙酸乙酯相比,丙酮提取效果较差(P<0.05),考虑到试剂毒性和提取效率,确定粉碎样品经乙醇超声提取30min作为最佳提取条件,在Waters CORTES-C18色谱柱上用乙醇:乙腈(30:70,v:v)等度洗脱,以发射波长296nm,激发波长272nm进行荧光检测,可有效分离出AR 5个同系物组分,标准曲线回归方程决定系数R2≥0.9999,线性范围0.050~10.0μg/ml;精密度实验相对标准偏差<5%,三水平加标回收率94.5%~104%;市售全麦含量ARs总量分别为小麦47.9~54.3mg/100g,黑小麦53.6~60.9 mg/100g。结论本研究建立的液相-荧光法能高效分离全麦中ARs并进行准确测量,具有操作简单、灵敏度高、快速有效的优点。

Objective To determine the quality of whole wheat products, it is necessary to establish a method for determination of alkylresorcinols （ARs） which are the markers of whole wheat, black wheat and other cereal products. Methods Taking wheat a-nd black wheat as main research objects, factorial design was used to investigate the effect of extraction reagents （acetone, alcohol, and ethyl acetate）, extraction methods （ultrasound for 30 rain, 60 rain, shaking at room temperature overnight）, and sample status （granule, flour） on the determination of ARs. And ARs detection conditions was established by comparing chromatographic conditions and scanning fluorescence wavelengths. The ARs content in some commercially available cereals were determined based on the methodological evaluation. Results Taking into account the toxicity of the reagents and efficiency, it was better that the comminuted sample was ultrasonically extracted with ethanol for 30 min before loading on the Waters CORTES-C18 column with ethanol： acetonitrile （30：70, v：v）. The fluorescence detector was set at a wavelength of 272 nm for excitation and 296 nm for emission to detect ARs. The linear range was 0.050-10.0 μg/ml and the coefficient R2≥0.9999. RSD of precision experiment was less than 5% and the spiked recovery rates of three levels were 94.5%-104%. The total amount of ARs was 47.9-54.3 mg/100g in commercially available wheat and 53.6-60.9 mg/100g in black wheat. Conclusion The liquid-fluorescence method established in this study can effectively and rapidly separate ARs from wheat and black wheat and has the advantages of simple operation, high sensitivity and accuracy.